80 Mr, Gnirrrru on the Development of 
occasionally reciprocally united by “suckers ;” in such there is actual com- 
munication between the ligneous systems*. 
With respect to the parts on which the parasitism occurs, J believe it is 
entirely dependent on the permanence of their nature. I have met with a 
solitary instance of the attachment and evolution of Loranthus on the leaf of 
a Guttiferous tree. The plant had reached the height of two inches, and had 
developed several leaves; no lateral shoot had been sent out. Its base was 
expanded on the upper surface of the leaf, and the sucker-like root had pene- 
trated the cuticle, and was firmly imbedded in the parenchymatous mesophyl- 
lum. Although in all probability this plant would, had it been left to its own 
fate, have perished, yet it might have become, before this had taken place, 
attached by a lateral shoot to a part capable of sustaining it by its permanent 
nature. Iam also of opinion that attachment will take place on any plant, 
or part of a plant, the duration of which is sufficiently long. "Those with 
milky juice, though perhaps a general, are not an universal exception. 
I have met with a species flourishing on the Artocarpus integrifolia. The 
juice of this species was not milky; it is hence obvious that they have an 
eliminating power, although the fact stated by De Candollet of coloured fluids 
passing into their tissue through the stock would lead us to suppose other- 
wise. 
With respect to the bourrelets formed round each attachment, they are 
occasioned by the deposit of new wood round their bases; they are often 
irregular, the upper part being, as might be expected, somewhat more de- 
veloped. 
I have never seen any secondary roots sent off either into the interior of the 
wood, or between the bark and wood y 
* Te will be interesting to compare this with grafts, on which subject I am quite ignorant. I think 
the attachment of Loranthus is not analogous to grafts, 
T I have seen seeds of Loranthus germinating on the succulent fronds of a Polypodium. 
? Physiologie Végétale, vol. ii. p. 790 ; and vol. iii. p. 1411, 
$ I have before mentioned that in one species of Viscum both primary and secondary external at- 
tachments take place. A slight examination of another species, in which no lateral shoot had been 
developed, leads me to suspect that the mode of adhesion of Viscum album is not thoroughly under- 
perhaps, 
